Assessing the Peripheral Levels of the Neurotransmitters Noradrenaline, Dopamine and Serotonin and the Oxidant/Antioxidant Equilibrium in Circus Horses.
Authors: Cocco Raffaella, Sechi Sara, Rizzo Maria, Arrigo Federica, Giannetto Claudia, Piccione Giuseppe, Arfuso Francesca
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Concerns about welfare in circus environments prompted researchers to compare blood biomarkers of psychological and physiological stress in 56 circus horses across five Italian circuses against a control group of conventionally managed horses. Using plasma analysis, the team measured three neurotransmitters—noradrenaline, dopamine and serotonin—as indicators of mental state, alongside oxidative stress markers (reactive oxygen metabolites and biological antioxidant potential). Surprisingly, no significant differences emerged between circus and control horses in any neurotransmitter or oxidative stress parameters, suggesting that the circus horses in this cohort were not experiencing measurable psychological distress or acute oxidative imbalance. However, a notable age-related finding warrants attention: horses aged 16–21 years showed significantly reduced antioxidant capacity compared to younger age groups, despite similar oxidative metabolite levels, indicating greater vulnerability to oxidative stress as they age. For practitioners, these results suggest that circus management itself—at least in the facilities studied—was not acutely compromising mental health status, but the data underscore the importance of enhanced nutritional and health management strategies for older performing horses to support their antioxidant defences.
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Practical Takeaways
- •Circus management in this study population did not appear to compromise equine mental status or create oxidative stress compared to conventional riding management, suggesting welfare concerns may be management-dependent rather than circus-inherent
- •Older horses (16+ years) require enhanced nutritional and care strategies to support antioxidant capacity, as their biological antioxidant potential declines significantly with age regardless of management type
- •Regular monitoring of antioxidant markers in aging circus and working horses may help identify susceptibility to oxidative stress and enable preventative management adjustments
Key Findings
- •Plasma concentrations of noradrenaline, dopamine, and serotonin showed no significant differences between circus-managed horses and conventionally ridden control horses (p > 0.05)
- •Reactive oxygen metabolites (d-Roms) and biological antioxidant potential (BAP) values were similar between circus and control groups (p > 0.05)
- •Horses aged 16-21 years exhibited significantly lower BAP values compared to younger age classes (4-5, 6-10, 11-15 years), indicating reduced antioxidant capacity with age (p < 0.05)
- •No breed-related differences were found in any neurotransmitter or oxidant/antioxidant parameters investigated (p > 0.05)